Radiotelegraphy-station.



GRAF GEORG VON ARCO, AUGUST LEIB & AUGUST FREYv RADIO'TELEGR'APHY STAT ION. APPLICATION FILED N0v.-1; 19

1;,1'78',89'0 PatentedApf.11,1916.

2 SHEETS-SHEET 2.

' Messier).

stares imam ore-rice.

GRAF enoae VON ARGO Ann AUGUST LEIB, 0F BERLIN, Ann AUGUST FREY, or non- NENDAMM, NEAR BERLIN, GERMANY, ASSIGNORS TO GESELLSCHAFT FUR DRAHT- LOSE TELEGRAPHIE, M. B. 11., or BERLIN,- GERMANY.

mpIoTELEeRAPHY-sTATmn.

' radio-telephonic station-employs only one antenna or aerial which isconnected with the transmitting apparatus for transmitting and withfithe receiving apparatus for receiving. The change over from the transmitting into the receiving position, and revusely,

has until recently been brought about by special, manually-operated. switches. Re-

cently, it has been'frequently desirable to be able to reverse in dependence on the key in such .manner that when the key is depressed the apparatuses are connected 'for transmittlng whereas when the-key is released they automatically return to the re-.

ceiving position. Various means for this purpose have been known heretofore. The technical difliculties met with areprincipally that the switching devices must synchrotron? follow the movementsof the key, the 'di cons1sts 1n the parts, improvements and, combinations more particularly described culties being increased still more by-theunterruption of circuits, 111 part carrying hlgh tension currents. Consequently, 1n some what large stationsthere is a very great eX- According to the invention theswit ching'r device is provided with meanssuch that, when the key is released a changeover-fromthe' transmitting into the receiving position does not at once .take place, while these means exercise no influence or do not necessarily exercise any influence on the re verse movement from-"the receiving intothe transmitting position. Therefore in this arrangement the apparatuses no longer re- (to be brought about by simply In addition, having 7 Specification of Letters Patent. Patented Apr, 11 191a Applicatic filed November 1, 1911. Serial No. 658,063. 7

turn again into the receiving position whenever ,the key is released when the subsequent movement of the key takes place earlier than the change-over occurs. Suc'haswitchlng arrangement which acts slowly one way may be employed for any desired modes of connections of the stations; the receiving and transmitting apparatuses may be connected in series, in which event the receiver will be short-circuited whenthe transmitting apparatus is being used, or the receivlng and transmitting apparatuses may be alternately interpolated in the antenna.

In these cases the operations tov be brought about by a slow-acting relay are as follows If, after finishing transmitting, receiving is to take place, firstly the primary heavy current must be interrupted, secondly the transmitting apparatuses must be disconnected, from the antenna, and, thirdly, the receiving apparatuses must be connected with the antenna; When it is required to change over from the receiving position to transmitting, firstly the receiving appara-v tusesmust be disconnected from the an-' tenna, secondly the transmitting apparatuses must be connected to the antenna, and,

thirdly, the transmitting heavy current circuit must be closed. All these functionsare depressing and releasing the key.

WVith these objects in view, the invention hereinafter and pointed out in the claims.- The invention is represented by way of example in the accompanying drawings,

wherein Figure 1 is a diagram showing thecomplete connection of a. station in ,Which thea position in which the antenna is connected with the transmitting circuit. a. A

The generalarrangement ofthe transmitting and rec'elv ng circuits and their connections with the antenna is in substance alike in both modifications shown in the Figs. 1 and 2.

' paratus 3.

lay coil 5 is energized by the battery 6, and

. the core 7 of this coil is attracted. The

bridge 8 of the relay is lifted from the lower contacts 38 and closes the upper contacts 9, and now current flows from the battery 6 over the contacts 9 to the coil 10, then over the contact spring 11 and the contact piece 12, which is rigidly connected with the rod 14:, back to the battery. In the coil 10 is an iron core 13 which is connected with asecond iron core 15 of a coil 16 by the rod 14 composed of non-magnetizable material. The coil 16 has a contact spring 17 si1nilar to the spring 11. VVhe'n the coil 10 is energized the iron core 13 is drawn to the right .into it, the spring 11 no longer contacts with the contact piece 12 and the contact 17, 12 is closed. The movement of the cores 13,

15 is imparted to a rod 18 for actuating the knife switch 2 and the spring pressed contact brush 20, which bears against plates 21 when closed. To this end, the rod 18 is pivotally attached to the relatively short arm 36 of the knife switch 2 and is provided with a slot 18 in which the relatively long arm 37 integral with a cam or eccentric 19 is guided. On this cam rests contact brush 20. Consequently, the same movement of the rod 18 imparts to the, switch 2 a long stroke of small power and to the brush 20 a short stroke of great power. Accordingly, the change-over of the apparatus is brought about by a system comprising two coils each of which tends to draw into its middle portion an iron core. One of these coils switches the apparatuses to transmitting I and the other to receiving.

As soon as the rod 18 is moved to the right the. switch 2 is. opened,-the contact brush 20 is powerfully pressed against the contact' pieces 21 and the condenser circuit is-connected to the antenna. This condenser circuit comprises the capacity 22, self'induction 23 and the spark-gap 24:. The elements are shown in this position in Fig. 3.

When the key 4 is depressed a current simultaneously flows, however, through a relay coil 25 whereby its core 26 is lifted against the contacts 27. The current from the alternating current machine 28 is hereby conducted over transformer winding 30, the

contacts 34 35, (which are then closed by bridge 35, as will be explained hereinafter) contacts 27 and a choking coil 29; consequently a current is induced in the secondcircuit.

is depressed the relay core 7 should be rapidly attracted, whereas when the key is released it should not at once close the contacts 38 again, because this would at once cause the arrangement to be returned to r ceiving. This is brought about by connecting the relay core 7 with a hydraulic or pneumatic brake'which may llifle the form of a dash pot. This dash pot comprises a cylinder 39 in which moves the piston 10 coupled with the relay core 7. The cylinder is provided with a check valve 41 whirallows the contents of the cylinder to freer issue therefrom when the piston rises, but not to reenter same. A small lateral opening whose size can be adjusted as desired by a regulating screw 42, serves for the gradual admission of the fluid, in this case air. In

- this manner we attain that the br lge 8 con tacts with the lower contact pied 38 only several seconds after the key 4: has been released.

Now it must be arranged that the heavy current circuit can be closed by the key relay 25, 26 only after the changeover of the antenna from the receiving into the transmitting position is terminated. Otherwise, in the case of deficient attention, the heavy transmitting currents would be able to pass through the receiving apparatus and destroy the same. For preventing this possibility the following arrangement is made: The knife switch 2 has connected with it an additional contact arm 43 which closes the contacts 32 only after the knife switch has been opened. These contacts are connected over the battery 6 with the relay coil 33. When the contacts 32 are closed the. coil 33 receives current from the battery 6, at tracts its armature 34 and closes the alternating current contacts 35 by means of bridge 35. .Accordingly, the alternating current can only now flow through the trans.- former 30, 31 and the transmitter can only now be thereby energized. If, on the other hand, the operators key is .released, a longer period than the dash pot permits its p iston to descend, bar 8 again has arrived at its low position, wherein it closes contacts 38 so that thereby a circuit is closed from battery 6 over contacts 38, solenoid 16, contact spring 17, plate 12 (which latter is then in 1. This likewise shifts rod18to; the left and thereby opens first contacts 32 and thus opens the generator circuit at 35, and thereupon knife switch 2 is closed, which again connects the antenna 1 to the receiver circuit. Simultaneously plate 12 slides ofi' contact'l'? and onto 11 and thereby sets the circuit for energizing solenoid 10. However,

the movement of cam 19, which operates freely oscillate for a certain time. -When the atmosphere is highly charged electrically a short moment of free electric oscillation would suffice for charging the antenna and for discharging it with great force at the receiver ground. This discharge would then take place over the detector and destroy the same.

In the illustrative embodiment according to Fig. 2 the contacts are directly controlled by the telegraph key 4, which is pivoted at 4 by means of an insulated portion so that no electrical connection exists between battery 6 and key 4.

When transmitting is to take place the key 4 is moved .out of the position shown in dotted lines into the transmitting posi-v tion shown in full lines. 'The rear end of the key is connected with a switch 44 which alternately connects the negative pole to battery 6 in circuit with one of the two contacts 45, 46. Fig. 2' shows thedevice inthe condition 'in which switch 44 has just been closed, so that the direct current consequently fiowsfrom the negative pole over switch 44, contact 45, coil 10 and contacts 11 12, to the positive'pole of battery 6. As

' mentioned with reference to Fig. 6, the core 13 is thereby attracted, the receiving contact 2 opened and the transmitting contact 20, 21 closed. After these latter contacts are closed and antenna 1 is connected in to the secondary oscillation circuit of the trans-' mitting system,"lower switch 43, 32 is closed which similarly to the manner described and shown in Fig. 1, closes a circuit over battery 6 which energizes relay coil 33, which by attracting its core 34' closescontact points 35 through bar 35 so that the circuit from generator 28 over inductance29, key 4, contacts'35,'primary coil 30 is set thereby, ready. to be closed by key 4 at its contacts 47, 47 when signals are to be transmitted.

The switch 44 which is insulated from the closed and the contact 4, 47 for the trans,

mitter relay is closed only alternately. lVhen receiving is to take place again, the key is lifted into the position shown in dotted lines and then drives the switch 44 lines.

into its position likewise shown indotted This breaks the circuit'through relay 10 and closes the circuit through relay 16 with the same effect as described before with reference to Fig. 1,, so that thereby the generator circuit is first interrupted at 35,

35, then the antenna connected by switch 2 to the receiver circuit and then disconnecttion when it is open, and means for preventing the switching devices from moving into their receiving position when the key moves from its transmitting position during the normal succession of the elements of the signaling code. I

2. In a radio-telegraphicstation, the combination of an antenna, means comprising a transmitter feeding circuit for generating electric oscillations, having-a key, means for transmitting and means for receiving oscillations, a switching device comprising a pair of receiving contacts for connecting the receiving means to and disconnecting the same' from the antenna, a second switching device comprising a pair of transmitting contacts for connecting the transmitting means to. and disconnecting the same from the an.- tenna, a common" actuating device for both of said switching devices for alternately opening and closing said devices, said key being adapted to cause the movement of the I said actuating device when the key moves into or out of. transmitting position, and means for preventing the switching devices from moving into their receiving position when the key moves from its transmitting position during the normal succession of the elements of the signaling code. I

3. In a radio-telegraphic station, the com bination of an antenna,.means comprising a transmitter feeding circuit for generating electric oscillations, having a key, means for transmitting and means for receiving oscillations, a switching device comprising a pair of receiving contacts for connecting the receiving means to and disconnecting the same from the antenna, a second switching device comprising a pair of transmitting contacts for connecting the transmitting means to and disconnecting the same from the an tenna, a common driving device for said switching devices, said key being adapted to key moves from its transmitting position during the normal succession of the elements of the signaling code.

4. In a radio-telegraphic station, the combination of an antenna, means comprising a transmitter feeding circuit for generating electric oscillations, having a key, means for transmitting and means for receivingelectric oscillations, a switch comprising a lever having onelong and one short arm for connecting the recelvmg means to and dlscon- =necting the same from the antenna, a contact brush having'a large contact face for connecting the transmitting means to and dis connecting the same from the antenna, a lever having unequal arms for moving said brush, a common driving device attached to the short arm of the former lever, and the long arm of the latter lever, two relay cores, a rod of non-magnetizable material connected with said cores and said driving device, two relay coils surrounding said relay cores, a key for closing and opening the transmitter feeding circuit and for energizing said relay coils, and means for preventing the said levers from being actuated when the key is opened during the normal succession of the elements of the signaling code.

5. In aradio-telegraphic station, the combination of an antenna, means comprising a.

transmitter feeding circuit for generating electric, oscillations, having a key, means for transmitting and means for receiving oscillations, switching devices and electromagnetic operating 'means therefor for alternately connecting said-transmitting and receiving means into and disconnecting. the same from the said antenna, comprising a change-over switch operatively connected with said'electro-magnetic means, forcausing in one of its positions the connection of the receiving means and in the other position of the transmitting means to said antenna. said key having lost motion connection with the said change-over switch to permit freedomof key movementat a small throw for transmitting telegraphic signals without opcrating the switch, but to cause operation of said switch at a large throw of said key.

6. In a radio-telegraphic station, the combination of an antenna for generating electric oscillations, having a key, means for transmitting and means for receiving oscillations, switching devices for alternately 1,17s,sso

connecting said transmitting and receiving means and disconnecting the same from the said antenna, said key being 'adapted to cause the movement of said'swit'ching devices, and means forretarding the disconnection of the transmitting means and the connection of said receiving means by said switching devices, said retarding means adapted to permit an unretarded disconnection of said receiving means and connection of said transmittin means by said switching devices.

7 In a radlo-telegraphic station, the com-,

bination of an antenna, means comprising a transmitter feeding circuit. for generating electric oscillations, having a key. means for transmitting and means for receiving oscil-,

lations, switching devices for alternately connecting said transmitting and receiving means to and disconnecting the same from the said antenna, said key being adapted to cause the movement of said switching devices. and regulat'able means for retarding the disconnection of the transmitting means and the connection of said receiving means by said switching devices, said retarding means adapted to permit an unretarded disconnection of said receiving means and connection of said transmitting means by said switching devices.

8. In a' radio-telegraphic station, the combination of an antenna, means comprising a transmitter feeding circuit for generating electric oscillations, having a'key,,means for transmitting and means for receiving oscillations, switching devices for connecting said transmitting and receiving means to and disconnecting the same from the saidantenna, relays controlled by said key for actuating said switching devices, and means controlled by said key for preventing the switching devices from moving into their receiving position when the key moves from its transmitting position during the normal succession of the elements of the signaling code.

9. In a radio-telegraphic station, the combination of an antenna, means comprising a transmitter feeding circuit for generating electric oscillations, havinga key, means for transmitting and means for receiving oscillations, switching devices for alternately connecting said transmitting and receiving means into and disconnecting the same from the said antenna, a relay controlled by said key for closing and opening the transmitter feeding circuit, a second relay directly controlled by said key for controlling the operation of said switching devices, and means connected with the latter relay for retarding the change-over of the switching devices from the transmitting into the receiving position, said means permitting unobstructed movement of said devices from the receiving into the transmitting position.

10; In 'a radio -te legraphic" station, the combination of an antenna, means comprising a'transmitter feeding circuit, for gen-- eratingelectric oscillations, having a key means for transmitting and means for receiving oscillations, switching devices for alternately connecting saidv transmittingand recelving means to ,and' disconnecting the, same from the said antenna, ,'said key being adapted to cause the -movement of said switching devices, means for blosing' said feeding circuits, means connected with the switching devices for causing: said closing means to-operat'e only after the receiv- 7 mg means are disconnected from the antenna, and means for preventing the swltching devices from immediately. moving .into,

their receiving positionfwhenthe key moves from its transmitting position.

11. In a radio-telegraphic station, the

combination of an antenna, means compris mg a transmittef feeding circuit for generating electric oscillations, having a key,

means for transmitting and means for receivmg oscillations, swltchmg dev ces 'for connecting said transmitting and receiving means to and disconnecting the same from the said'an'tenna, said key being adapted'td cause the, movement of said switching devices, means for closing said feedingcircuit, means connected with the switching devices for causing said closing means to 0perate only after the receiving means are disconnected from the antenna,-and means for preventing the switching devices from immediately moving into their receiving position when the key. moves from its transmitting.position.

In testimony whereof we ai fix our sig-". 

